1. Technical Field
The invention relates to a display device and a display panel thereof, and in particular, to a touch display device and a touch display panel thereof.
2. Description of Related Art
With the technical development of the display panel with touch function (touch panel), the touch display panel is widely integrated to the electronic device. The in-cell touch display panel is the trend in particular. The characteristic of the touch display panel is the integration of the display panel circuit and the touch panel circuit. The combined routing allows displaying and touch controlling at the same time and is lighter as well as thinner. The touch panel circuit comprises the driving electrodes and the sensing electrodes. The material of both the driving electrodes and the sensing electrodes can be the transparent conductive material or the metallic material.
However, the resistance of the transparent conductive material is higher than the resistance of the metal material. As a result, the RC loading of the transparent conductive material is higher than that of the metal material. Thus, the size of the transparent conductive material is limited to smaller scale. On the other hand, the opaque metal material decreases the open ratio (aperture ratio) of the device. In order to decrease the impact of the metallic sensing electrodes and the metallic driving electrodes to the open ratio, the metallic sensing electrodes and the metallic driving electrodes are hidden above of the data electrodes or the scan electrodes for shadowing. The top of the data electrode refers to a viewing angle looking down to the data/scan electrodes.
In general, the driving electrodes generate a positive polarity voltage signal to form a touch induced capacitance with the sensing electrodes, so as to detect touch action. However, the backchannel of the thin-film transistor adjacent to the driving electrodes might be incorrect operation by the above-mentioned touch induced capacitance coupling effect. The incorrect operation results in the voltage disturbance of the pixel electrode, affects the accuracy of the output grayscale voltage of the pixel, and eventually causes poor display effect.